If you ask me, he does have a Sokka flavor to his attitude. His smile is big as his, and in the last one, where he is serious, it does look like when Sokka is serious. And they nailed the haircut, completely.

My only complaint, is that the hair on top is cut a little too deep on the sides. It could be trimmed a little more off. The facial features (eyes and chin) really suit Sokka, it's a nice interpretation.